It has become apparent that gas emissions from vehicles (such as automobiles) can contribute to air pollution, especially in particularly congested areas, such as large cities. Accordingly, modern vehicles are equipped with sophisticated emissions systems that are configured to reduce harmful emissions from the vehicle. These vehicles are also equipped with a variety of sophisticated emissions-related devices for informing the vehicle's owner and vehicle technicians if the vehicle's emissions systems are not functioning properly.
One such emissions-related device is a “check engine” light (or malfunction indicator light), which is commonly located on the vehicle's dashboard. Such “check engine” lights are typically configured to illuminate when the vehicle's on-board computer detects a problem with the vehicle's emissions system.
The vehicle is also equipped with a variety of emissions-related sensors that are configured to monitor (either continuously or intermittently) various aspects of the vehicle's emissions system. These sensors are configured to transmit data to a computer within the vehicle for analysis by the computer. If the computer determines that data from one or more of the sensors is indicative of a problem within the vehicle's emissions system, the computer activates one or more system error indicators (which are commonly referred to as readiness monitor points or “flags”). These system error indicators are then used to help technicians diagnose and repair the vehicle's emissions system. In addition, the system error indicators may be used by state-certified emissions testing authorities to determine whether the vehicle meets state emissions standards.
In many states, such as Georgia, in order for a vehicle to pass a regularly scheduled emissions test, the vehicle's “check engine” light must be off, and the vehicle must not have any currently active system error indictors (e.g., the vehicle's OBD II readiness monitors must not indicate that there is a problem with the vehicle's emissions-related systems or components). If a vehicle fails inspection, the owner typically takes the vehicle to a mechanic who uses a diagnostic tool, such as a “scan tool”, to determine which of the vehicle's system error indicators are currently active. The mechanic then uses this information to determine which, if any, specific repairs are needed to bring the vehicle into compliance with emissions standards.
Once the repairs are done, it is necessary to deactivate or “reset” any active system error indicators. To do this, a technician typically puts the vehicle through a “drive cycle”, such as the Ford P1000, I/M Readiness Code Drive Cycle. As will be understood by one skilled in the art, during the “drive cycle”, the vehicle is operated in various prescribed ways for specified periods of time.
When putting the vehicle through the drive cycle, the technician also activates various vehicle systems, such as the vehicle's air conditioning system. If all of the vehicle's systems are functioning properly, and if the drive cycle is executed properly by the technician, all of the vehicle's active system error indicators will reset automatically in response to the vehicle being put through the drive cycle. Technicians typically attach a scan tool to the vehicle while performing the drive cycle to manually verify, in real time, that the vehicle's system error indicators are resetting properly.
Once the technician determines that all of the vehicle's system error indicators have reset properly, the vehicle's owner takes the vehicle back to an emissions testing facility where an emissions tester verifies that the vehicle's check engine light is not illuminated, and that none of the vehicle's system error indicators are “active” (e.g., that the current status of all the vehicle's readiness monitors is “ready”). Once this verification process is complete, the vehicle is certified as having passed the emissions test.
One problem with the current emissions testing process is that the prior art process of resetting active system error indicators is unnecessarily time-consuming. This is due to the fact that standard drive cycles typically require that the vehicle be driven for at least 40 minutes to properly complete the drive cycle. In fact, it commonly takes an hour or more to properly reset a vehicle's system error indicators using prior art techniques.
Another problem with current emissions testing processes is that the prior art process of resetting active system error indicators is often difficult and unsafe. This is due to the fact that standard drive cycles often require that the vehicle be driven in a rigorously prescribed manner in order to reset the various system error indicators. For example, the Ford drive cycle referenced above requires that a driver drive the vehicle continuously for 10 minutes at a speeds of 45–65 mph while avoiding sharp turns and hills. This can be difficult and unsafe to achieve in certain settings, especially on the congested roadways common to most major cities.
Accordingly, there is a need for an improved method and apparatus for resetting active emissions system error indicators that may be performed quickly and safely.